Rebus - Run unit tests and wait for Rebus to complete all threads - rebus

Question

I am building an integration test where I am using InMemNetwork to run the test.
There is a Thread.Sleep call just before an assert but that is a dodgy way of testing and it slows down our tests a lot.
I am also doing some integration tests using SagaFixtures and a simple IBus implementation that runs synchronously but its all a bit tedious with registering handlers, running handlers and deferring messages.
Is there a way to wait on all threads in use by Rebus until they are finished executing without augmenting production code using things like ManualResetEvent (used in Rebus own tests)?

Answer 1

I usually use SagaFixture as you do, and then I use FakeBus to inject into saga handlers in order to capture their actions.
Most of my tests are unit tests of simple handlers though, but I will often inject "real" service, like e.g. implementation of IThis and IThat that go to a real database.
For a couple of scenarios though I spin up multiple endpoints with an in-mem transport, and then I usually implement an extension on InMemNetwork that helps me wait for particular events to be published or something like that – it could look like this in a test:
var updated = await Network.WaitForNext<WhateverUpdated>(subscriberAddress, timeoutSeconds: 20);
where WaitForNext is simply an extension method that polls the queue specified by subscriberAddress for the next message and tries to deserialize it as WhateverUpdated.
I hope that can give you some inspiration :)

Answer 2

For some scenario's I use the following approach to wait for Rebus to complete all message processing. The rebus endpoints are hosted in separate exe's and the rebus filesystem transport is used for integration tests (normally it's Azure SB). The integration test spins up the exe's and in each exe Rebus is configured with 0 workers, so it's doing nothing. Then in the test we have a WaitForMessagesProcessed() method that configures a number of workers and blocks until there are no more messages to be processed.
Here is how it roughly looks in code:
public class MessageProcessor() {
private string queueName;
private int messagesWaitingForProcessing;
private IBus bus;
public MessageProcessor(string queueName) {
this.queueName = queueName;
this.bus = Configure.With(adapter)
.Transport(t => t.UseFileSystem(#"c:\baseDirectory", this.queueName))
.Options(o =>
{
o.SetNumberOfWorkers(0);
})
.Events(e =>
{
e.BeforeMessageSent += (thebus, headers, message, context) =>
{
// When sending to itself, the message is not queued on the network.
var m = context.Load<Rebus.Pipeline.Send.DestinationAddresses>();
if (m.Any(t => t == this.queueName))
this.messagesWaitingForProcessing++;
};
e.AfterMessageHandled += (thebus, headers, message, context, args) =>
{
this.messagesWaitingForProcessing--;
};
})
.Start();
}
public async Task WaitForMessagesProcessed()
{
this.DetermineMessagesWaitingForProcessing();
while (this.messagesWaitingForProcessing > 0)
{
this.bus.Advanced.Workers.SetNumberOfWorkers(2);
while (this.messagesWaitingForProcessing > 0)
{
await Task.Delay(100);
}
this.bus.Advanced.Workers.SetNumberOfWorkers(0);
this.DetermineMessagesWaitingForProcessing();
}
}
public void DetermineMessagesWaitingForProcessing() {
this.messagesWaitingForProcessing = Directory.GetFiles(GetDirectoryForQueueNamed(this.queueName), "*.rebusmessage.json").Count();
}
private static string GetDirectoryForQueueNamed(string queueName)
{
return Path.Combine(this.baseDiretory, queueName);
}
}
A test could be like
[TestMethod]
public void Test() {
var endpoint1 = LaunchExe("1");
var endpoint2 = LaunchExe("2");
endPoint1.DoSomeAction();
endPoint1.WaitForMessagesProcessed();
Assert.AreEqual("expectation", endPoint1.Query());
}